Hi I am new to Mathematical Logic and recently I self-tutored on natural deduction. I have learned natural deduction rules like:
Rule for $\wedge$-formula.
Rule for $\rightarrow$-formula.
Rule for $\bot$ and RAA.
Can anyone help me in proving this formula?
$$(S\rightarrow \neg R) \rightarrow ( S\rightarrow R)$$
By natural deduction using the above rules or any related rules to learn more.
You should check it with truth table as @MauroALLEGRANZA commented. This formula is not tautology (that is, it is not true in any interpretation). One may prove only a tautology (well, in consistent logic). So, there is no natural deduction proof of this formula.